JP2007309446A - Shaft coupling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft coupling of a type for transmitting power between two parallel shafts via a cylindrical rolling element arranged at a crossing position of guide grooves perpendicular to each other, having improved torque loading capability while preventing a trouble caused by the inclination of the rolling element. <P>SOLUTION: Sliders 9 which are engaged with a cage 4 for constraining the rotation of a shaft (the cylindrical rolling element) 3 in a plane including its axis are provided on both sides of the cage 4. The sliders 9 opposing each other across the cage 4 are connected to each other with a connection member 11 which passes through an oblong hole 7 of the cage 4 and retaining rings 12 are mounted at both ends of the connection member 11 engaged with the outside face of the slider 9 to constrain the separation of the sliders 9 from each other. This improves torque loading capability while preventing the shaft 3 from being bitten into the guide grooves 5, 6 and avoiding vertical drag forces which the slider 9 receive from the cage 4 from being transmitted as tensile forces to the shaft 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shaft coupling that couples two parallel shafts to transmit power between the two shafts.

  A shaft joint that connects two shafts of a general mechanical device and transmits power from the drive side to the driven side has a different structure depending on the positional relationship between the two shafts to be connected. And those that are parallel to each other (and not concentric).

As a shaft coupling for connecting two parallel shafts, the present applicant proposes a method for transmitting power via rolling elements arranged at the intersections of guide grooves orthogonal to each other between the two parallel shafts. (See Patent Document 1).
JP 2005-172217 A

  FIG. 5 shows an example of the above-described shaft coupling (see Japanese Patent Application No. 2005-154090). In this axial joint, a plurality of guide grooves 53 and 54 are provided on two rotating members 51 and 52 facing each other in the axial direction so as to be orthogonal to the guide groove on the other side. (Moving body) 55 is arranged, both end portions thereof are guided by the respective guide grooves 53, 54, and the central portion is passed through the elongated hole 57 of the retainer 56 and held. FIG. 5 shows a state in which both the rotating members 51 and 52 are concentric for the sake of explanation, but normally, they are used in a state in which the rotational axes of both are shifted (eccentric).

  The shafts 55 are in rolling contact with the recesses 53a and 54a of the guide grooves 53 and 54 via rolling bearings 58 fitted on the outer circumferences of both ends. Further, the central portion of the shaft 55 is passed through sliders 59 on both sides of the cage 56, and rolling that rolls in the long holes 57 of the cage 56 on the outer periphery of a connecting member (column member) 60 that couples both sliders 59. The bearing 61 is fitted, and the shaft 55 is in a state in which movement of the rotating member in the radial direction is restricted by the cage 56. In this state, the shaft 55 is pushed by the driving-side rotating member 51, thereby pushing the driven-side rotating member 52 while rolling inside the guide grooves 53, 54 and the long hole 57 of the cage 56, thereby generating power. introduce.

  Here, the slider 59 includes the axis of the shaft 55 by engaging with the retainer 56 in a state where the shaft 55 that receives forces having different operating points and directions from the rotating members 51 and 52 and the retainer 56 is passed. By restricting the rotation in the plane, the trouble that the shaft 55 is inclined with respect to the axial direction of the rotating member and bites into the guide grooves 53 and 54 is prevented.

  By the way, in this shaft coupling, when each slider 59 receives a rotational moment generated in the shaft 55 and presses the cage 56, it receives a vertical drag from the cage 56, and the vertical drag couples both sliders 59 together. The friction between the connecting member 60 and the inner peripheral surface of the mounting hole 59a into which the end of the connecting member 60 is inserted cannot be supported. Therefore, retaining rings 62 are attached to both ends of the shaft 55 in order to restrain the movement of each slider 59 in the direction away from the cage 56. However, in this structure, the force received by each slider 59 from the cage 56 is transmitted as a tensile force to the shaft 55 via the retaining ring 62, and the shaft 55 is subjected to bending force from both the rotating members 51, 52 and the cage 56. And the tensile force are simultaneously received, the strength of the shaft 55 is insufficient and the torque load capacity is lowered.

  An object of the present invention is to prevent a trouble caused by the inclination of a rolling element in a shaft coupling of a system that transmits power via a cylindrical rolling element arranged at the intersecting position of guide grooves orthogonal to each other between two parallel axes. It is to increase the torque load capacity.

  In order to solve the above-described problems, the present invention provides a plurality of linearly extending guides on opposing surfaces of two rotating members that are axially opposed and are held in a state where the rotation axes are parallel to each other and not concentric. A cylindrical shape is provided in which a groove is provided so as to be orthogonal to a guide groove at a corresponding position of the counterpart rotating member, and the guide grooves of both the rotating members intersect with each other, and both ends are guided by the guide grooves to roll. A rolling element is provided, and a retainer for restraining movement of each rolling element in the radial direction of the rotating member through a central portion of each rolling element is provided in a linear long hole having a predetermined angle with each guide groove, In the shaft coupling adapted to transmit power between the rotating members via the rolling elements, the cage and the cage with the rolling elements being passed through the through holes between the rotating members and the cage. A slider that engages and restrains rotation in a plane that includes the axis of the rolling element is provided. The slider each other opposite each other across the cage, as well as connected by a connecting member passing through the long hole of the cage, provided with means for constraining the separated of each other the slider.

  That is, by providing a slider that engages with the cage and restrains rotation in a plane including the axis of the rolling element on both sides of the cage, and restrains the separation of the sliders facing each other across the cage, Keep the rolling element parallel to the rotating member axial direction with the slider to prevent the rolling element from being caught in the guide groove, and to prevent the vertical drag that each slider receives from the cage from being transmitted to the rolling element as a tensile force. The torque load capacity was increased.

  In the above configuration, as means for constraining the separation of the sliders, a means in which retaining rings that engage with the outer surface of the slider are attached to both ends of the connecting member can be employed. Further, a male screw member with a head may be used as the connecting member, and the male screw member may be screwed from the outer surface of one slider to the other slider. Alternatively, a caulking portion that engages with the outer surface of the slider may be formed at both ends of the connecting member.

  As described above, the shaft coupling of the present invention is provided with sliders that engage with the cage and restrain rotation in a plane including the axis of the rolling element on both sides of the cage, and are opposed to each other across the cage. Since the separation between them is constrained, the rolling element can be prevented from getting caught in the guide groove and the joint operation can be stabilized, and the tensile force caused by the slider does not act on the rolling element. Since the rolling element is less likely to have insufficient strength, the torque load capacity can be increased as compared with the conventional slider.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4. 1 and 2 show a first embodiment. This shaft coupling is opposed to the plates (rotary members) 1 and 2 fixed to the input / output shafts A and B, which are opposed to each other in the axial direction and whose rotation shafts are held in parallel with each other. Are provided with a plurality of shafts (cylindrical rolling elements) 3 and a cage 4 that restrains the movement of each shaft 3 in the plate radial direction, and power is transmitted between the plates 1 and 2 via each shaft 3. To communicate. 1 and 2 show the state where the input / output shafts A and B are concentric for the sake of explanation, but the rotation shafts of the input / output shafts A and B are usually shifted (eccentric) as will be described later. Used in state.

  Each of the plates 1 and 2 is a donut-shaped disk, fitted into the outer periphery of the shaft end portions of the input shaft A and the output shaft B, and fixed in a state of being opposed in the axial direction. Each of the plates 1 and 2 is provided with a plurality of guide grooves 5 and 6 at equal intervals in the circumferential direction so as to be orthogonal to the corresponding guide grooves of the counterpart plate. The shaft 3 is incorporated in parallel with the plate axis direction.

  Each of the guide grooves 5 and 6 is formed so as to extend linearly, and concave portions 5a and 6a having a certain depth are provided on the inner surface thereof, and both end portions of the shaft 3 are formed by the concave portions 5a and 6a. Is to guide you. In addition, each guide groove does not necessarily need to penetrate a plate like this embodiment, and should just be provided in the opposing surface of both plates.

  The retainer 4 is formed in an annular shape, and a plurality of elongated holes 7 extending linearly in a direction forming 45 degrees with the guide grooves 5 and 6 are provided at equal intervals in the circumferential direction. And is held through the central portion of the shaft 3. On the other hand, the shaft 3 is fitted with rolling bearings 8 on the outer circumferences of both end portions thereof, and is in rolling contact with the recesses 5 a and 6 a of the guide grooves 5 and 6 via these rolling bearings 8. And between each plate 1 and 2 and the holder | retainer 4, the flat slider 9 engaged with the holder | retainer 4 in the state which passed the shaft 3 through the through-hole 9a is provided, and, thereby, the axis | shaft of the shaft 3 is provided. Rotation in the plane including is restricted. Further, a linear motion bearing 10 that is in rolling contact with the edge of the long hole 7 of the cage 4 is attached to the surface of each slider 9 facing the cage 4, so that the slider 9 can smoothly move relative to the cage 4. It is like that. In addition, the linear motion bearing 10 uses a needle roller incorporated in a flat cage. A sliding member (sliding bearing) may be provided instead of the linear motion bearing.

  Further, the sliders 9 facing each other with the cage 4 interposed therebetween are coupled by two columnar coupling members 11 penetrating the long hole 7 of the cage 4. Each connecting member 11 is secured to the slider 9 by attaching retaining rings 12 that engage with the outer surface of the slider 9 at both ends protruding from the outer surface of the slider 9. Then, a rolling bearing 13 that rolls in the long hole 7 of the cage 4 is fitted on the outer periphery of each connecting member 11, whereby the shaft 3 restrains the cage 4 from moving in the plate radial direction via the slider 9. It has become a state.

  Next, the power transmission mechanism of this shaft coupling will be described. When the input shaft A of the shaft coupling is driven to rotate and the plate 1 fixed thereto rotates, the shaft 3 pushed from the circumferential direction into the guide groove 5 of the input side plate 1 is moved by the retainer 4 to the plate diameter. Power is transmitted to the output shaft B by pushing the guide groove 6 of the plate 2 fixed to the output shaft B and rotating the output side plate 2 in a state where the movement of the direction is constrained. Even if the rotation direction of the input shaft A changes or the driving side and the driven side of the input / output shafts A and B are reversed, power transmission is performed by the same mechanism.

  At this time, each shaft 3 generates a moment of rotation because the acting point and direction of the force received from the plates 1 and 2 are not coaxial, but the shaft 9 is engaged by the engagement between the slider 9 passing the shaft 3 and the cage 4. Therefore, it is possible to maintain a posture parallel to the plate axis direction, and there is no possibility of biting into the guide grooves 5 and 6.

  The power transmission mechanism is basically the same even in a normal use state where the input / output shafts A and B are eccentric. That is, although illustration is omitted, when the input / output shafts A and B are decentered, the crossing position of the guide grooves 5 and 6 changes in the circumferential direction of the plate, and each shaft 3 has a long hole in the guide grooves 5 and 6 and the cage 4 The power is transmitted between the plates 1 and 2 while moving inside 7.

  This shaft coupling has the above-described configuration, and the connecting member 11 that connects the sliders 9 that are opposed to each other with the retainer 4 interposed therebetween is prevented from coming off by the retaining ring 12 and restrains the separation of the sliders 9. The vertical force that each slider 9 receives from the cage 4 acts as a tensile force on the connecting member 11 and is not transmitted to the shaft 3. Here, the connecting member 11 of the slider 9 receives a force from the cage 4 in a state where both ends are supported, and is designed to have a bending stress compared to the shaft 3 which receives a force from each of the plates 1 and 2 in a cantilevered manner. Can afford. Therefore, a higher torque load capacity can be obtained than a conventional shaft coupling having a structure in which a tensile force acts on the shaft.

  FIG. 3 shows a second embodiment. This shaft coupling uses a male screw member 14 with a head instead of the connecting member 11 of the slider 9 of the first embodiment, and the male screw member 14 is screwed from the outer surface of one slider 9 to the other slider 9. In this way, the separation between the sliders 9 is restricted. Note that a sleeve 15 is fitted between the rolling bearing 13 and the outer periphery of the body portion of the male screw member 14. By replacing the connecting member with a screw type in this way, it becomes easier to ensure the dimensional accuracy of the gap between the slider 9 and the cage 4, and the slider 9 moves more smoothly along the cage 4. Can do.

  FIG. 4 shows a third embodiment. In this embodiment, a concave portion is provided on the outer surface of the slider 9, and the caulking portions 16 a that engage with the concave portion are formed at both ends of the connecting member 16, thereby restraining the separation between the sliders 9. As a result, the accuracy of the gap dimension between the slider 9 and the retainer 4 can be improved as in the second embodiment, and the retaining ring 12 of the first embodiment and the sleeve 15 of the second embodiment are no longer necessary. The score can be reduced.

  The means for restraining the separation between the sliders facing each other with the cage interposed therebetween is not limited to the method described in the above-described embodiment. For example, both end portions of the connecting member that connects both sliders are welded to each slider. You may make it join.

Side view of the shaft coupling of the first embodiment II-II sectional view of FIG. Sectional drawing corresponding to FIG. 2 of the shaft coupling of 2nd Embodiment Sectional drawing corresponding to FIG. 2 of the shaft coupling of 3rd Embodiment Sectional view corresponding to FIG. 2 of a conventional shaft coupling

Explanation of symbols

1, 2 Plate (Rotating member)
3 Shaft (cylindrical rolling element)
4 Cage 5 and 6 Guide groove 7 Long hole 8 Rolling bearing 9 Slider 9a Through hole 10 Linear motion bearing 11 Connecting member 12 Retaining ring 13 Rolling bearing 14 Male thread member 15 Sleeve 16 Connecting member 16a Caulking portion A Input shaft B Output shaft

Claims (4)

  A plurality of linearly extending guide grooves are formed on the opposing surfaces of the two rotating members that are axially opposed and are held in a state where the rotation axes are parallel to each other and not concentric. Cylindrical rolling elements that roll while being guided by both ends of each guide groove are provided at positions where the guide grooves of the two rotating members intersect with each other. A retainer is provided in a linear long hole that forms an angle of through the central portion of each rolling element to restrain the movement of each rolling element in the radial direction of the rotating member, and between the two rotating members via each rolling element. In a shaft coupling adapted to transmit power, an in-plane including the axis of the rolling element by engaging the rolling element with the rolling element passing through a through hole between each rotating member and the cage. Provided with a slider that restrains rotation at the What was, while connected by a connecting member passing through the long hole of the cage, the shaft coupling, characterized in that a means for constraining the separated of each other the slider.   2. The shaft coupling according to claim 1, wherein the means for restraining the separation of the sliders attaches a retaining ring that engages with an outer surface of the slider to both ends of the connecting member.   The means for constraining the separation of the sliders uses a male screw member with a head as the connecting member, and the male screw member is screwed from the outer surface of one slider to the other slider. Item 10. The shaft coupling according to Item 1.   The shaft coupling according to claim 1, wherein the means for restraining the separation between the sliders forms a caulking portion that engages with an outer surface of the slider at both ends of the connecting member.

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